Over the past few decades, ethanol has become increasingly important as an alternative fuel. One advantage to use of ethanol fuel is that it can be produced from corn. Ethanol from corn is produced by either the wet-milling or dry-milling process. During the milling process, the corn kernels are ground, and the main constituents (starch, gluten, germ, and fiber) are separated and the starch is further processed to make ethanol. In dry corn milling the corn kernels are ground, and without additional separation, mixed with water and the mixture is further processed to make ethanol. The residue of the ethanol process is referred to as stillage. Stillage from dry corn milling contains a mixture of solids, oil, and water. A portion of the stillage is processed to extract the corn oil incorporated therein.
In the dry milling operation, a “beer” mash is made as a result of the fermentation process. The ethanol is removed from the “beer” in a stripper or distillation column. The remaining mash is referred to as whole stillage. This whole stillage is then subjected to centrifuging or other separation techniques to result in a thin stillage and a wet cake. This thin stillage is further processed in an evaporator or the like to remove excess water and produce a concentrated thin stillage stream called “syrup”. Typically, this syrup has a moisture content of between about 15-90 wt %. Increasingly, the syrup is treated via heat and centrifuge or other separation techniques to separate corn oil for industrial usage of the corn oil such as in biodiesel fuel.